Your observation is correct -there is a eight-character limit, and this could be a problem if your other nodes in the cluster are named jccmsdb3/4 and so on - the disk ids from all thse nodes could be same after truncating to eight characters.

For hostnames with 8 characters or more you must set the HP-UX tunable expanded_node_host_names to 1. (Default is 0). Starting with SFHA 6.0.1, the product installer advises you to set this tunable if it detects that the hostname is 8 characters or more on HPUX.

Also: ensure that the hostid in the /etc/vx/volboot matches the hostname command output.

If they differ, look for the steps under 'Veritas Volume Manager System Name' in the following link: